A fitting pressing member includes: a first opening that opens inside a fitting of an endoscope a second opening that is communicably connected to the first opening and is connectable to a fluid supply source a cylindrical portion formed from the first opening to a predetermined position, the cylindrical portion covering a part of a hollow portion communicably connected to the first opening and the second opening a narrowing portion including a side face whose outer diameter increases from the predetermined position toward the second opening, the narrowing portion covering the other part of the hollow portion and a plurality of grooves formed over a predetermined area from the predetermined position in an outer surface of the narrowing portion.
